UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (5,509)	$ (2,652)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization	86	38
Equity-based compensation	365	380
Amortization of long-term debt issuance costs and fees	24	50
Other	73	0
Change in fair value of warrant liabilities	128	(38)
Changes in operating assets and liabilities:
Unbilled revenue receivable and accounts receivable	8	(449)
Receivable from related party	(4)	(5)
Prepaid expenses and other current assets	311	(556)
Deferred offering costs	0	(241)
Other noncurrent assets	0	(19)
Accounts payable	(120)	58
Accrued expenses and other current liabilities	(8)	(1,581)
Deferred revenue	0	(1,982)
Other noncurrent liabilities	(1)	0
Net cash used in operating activities	(4,647)	(6,997)
Cash flows from investing activities:
Capital expenditures	0	(245)
Net cash used in investing activities	0	(245)
Cash flows from financing activities:
Proceeds from exercise of common stock options	7	43
Net cash provided by financing activities	7	43
Net increase decrease in cash and cash equivalents	(4,640)	(7,199)
Cash and cash equivalents - beginning of period	25,764	19,623
Cash and cash equivalents - end of period	21,124	12,424
Non-cash financing activities:
Issuance of common stock for professional services	436	0
Deferred offering costs (accounts payable and accrued expenses)	0	733
Capital expenditures (accounts payable and accrued expenses)	$ 45	$ 268